As a method of administering a nutrient to a patient who can not ingest a nutrient orally, generally, there are three administration methods of pervenous nutrient administration, stomach tube nutrient administration which is performed by inserting a nutrient tube into stomach or intestine nasally, and enteral nutrient administration though a gastric fistula. In recent years, with development of an enteral nutrient and a method of administering it, enteral nutritional management by percutaneous endoscopic gastrostomy (PEG) has been frequently performed. Since in PEG, a fistula is made by small operation, invasion is small as compared with surgical laparotomic gastrostomy, and a medical cost can be considerably reduced, therefore, PEG has become a standard format of gastrostomy in Europe and USA. The catheter kit for a fistula is for carrying out this PEG and, specifically, for percutaneously replenishing a nutrient or a drug solution into stomach from outside a body.
Previously, various catheter kits for a fistula have been proposed. Generally, the catheter kit for a fistula is constructed of a catheter having a lumen for replenishing a nutrient or a drug solution into stomach from outside a body, and an internal indwelling part provided at a tip part of the catheter, which is positioned in a body in the embedded state, and prevents the catheter from being evulsed from stomach. If necessary, the kit also has a flat extracorporeal fixing part at a rear end of a tube so that the tube is not embedded in stomach.
Hitherto, this internal indwelling part is usually formed of a balloon having a thin shell, and is constructed so that dilation and constriction of the internal indwelling part can be selected by supplying a fluid to the balloon and discharging a fluid from the balloon. However, when the internal indwelling part is a balloon-type, it is unexpectedly deformed due to damage such as rupture thereof, the embedded state of a catheter in stomach can not be maintained, and there is a possibility that the catheter is evulsed from stomach.
U.S. Pat. No. 4,863,438 which is a patent reference 1 discloses a catheter kit for a fistula which solves these disadvantages. This catheter kit for a fistula is provided with a non-balloon-type internal indwelling part which is elastically deformed by an external force and, in the free state, is in the state where it is projected from the catheter outwardly in its radial direction and, in the state where an external force is acted, a projection area obtained by projecting the internal indwelling part on the same axis as that of the catheter is reduced than that of the projected state.
According to the same manner as that of to this catheter kit for a fistula, when the catheter is inserted into stomach from outside a body, a rod-like obturator is inserted into a tip part of the catheter inside or outside the catheter and, by further pushing in the obturator, the internal indwelling part is pushed and extended elastically. In this state, the catheter together with the obturator is inserted into stomach. After insertion, by evulsion of only the obturator from the balloon, the internal indwelling part is returned to the projected state. Like this, since the internal indwelling part is a non-balloon-type, after the catheter is embedded in stomach, a possibility of unexpected deformation is small, and evulsion of the catheter from stomach is prevented, unlike a balloon type.
However, although it is disclosed that the catheter is inserted in stomach from outside a body via a fistula which has been already provided in a patient, a specific method therefor is not disclosed. When a fistula is provided, a penetrating pore is formed in an abdominal wall and a stomach wall of a patient with a needle or the like, and the catheter is inserted into the penetrating pore. Upon this insertion, a stomach wall is fixed with a suture thread so that the stomach wall is not freely moved relative to an abdominal wall, but actually, it is difficult to completely fix it, and when a stomach fistula is not properly provided, acute peritonitis is caused in some cases.
Japanese Patent No. 3347315 which is a patent reference 2 discloses a catheter kit for a stomach fistula 500 which solves a problem at provision of this fistula, and comprises a catheter 100, and has in an interior thereof a hollow rod 200 which is evulsibly engaged with an internal indwelling part 102 provided below a tube 101 and, in this engaged state, transmits an external force to the internal indwelling part 102 from outside a body and has an in-rod passage 202 through which a guidewire 400 is inserted, wherein the internal indwelling part 102 has a communicating passage 105 for making an in-rod-passage 202 communicate with a space in stomach in the engaged state, as shown in FIG. 21 and FIG. 22. The guidewire 400 is passed through the hollow rod 200, and the hollow rod 200 has function as an obturator.
Specifically, since central axes of penetrating pores 303 of a stomach wall 302 and an abdominal wall 301 are not consistent, and the catheter 100 can not be properly inserted, by passing the guidewire 400 through the penetrating pores 303, and aligning the penetrating pores 303 of an abdominal wall 301 and a stomach wall 302 along the guidewire 400, an insertion route for the catheter is made to be proper, the guidewire 400 is passed through the in-rod passage 202 and a communicating passage 105 in an assembly of the hollow rod 200 and the pushed and expanded internal indwelling part 102, and the catheter 100 is inserted into stomach from outside a body. However, in the catheter kit described in Japanese Patent No. 3347315, when the internal indwelling part 102 of the catheter 100 is elastically deformed from the free state into the external force acting state, since the guidewire passage 202 is passed through an operating part 201 of the hollow rod 200, the guidewire 400 becomes an obstacle when the operating part 201 of the hollow rod 200 is pushed with a finger, this makes a worker be conscious of avoiding the guidewire 400 (FIG. 22). Alternatively, it is also contemplated that the operating part 201 is configured to be greatly expanded outwardly in a radial direction of the hollow rod 200 so that the guidewire 400 does not become an obstacle. However, in this case, since a direction that the preparing part 201 of the hollow rod 200 is pushed with a finger is outside of a central axis of the hollow rod 200, there is a problem that a force is not effectively transmitted from the hollow rod 200 to the internal indwelling part 102 of the catheter 100.
On the other hand, since a whole catheter used in the previous catheter kit for a fistula is formed of an elastic material, when an external force is acted with an obturator or a hollow rod, not only an internal indwelling part, but also a tube which is not necessary to be pushed and expanded are pushed and expanded meaninglessly. That is, as shown in FIG. 22, a length l1 of the tube 101 in the free state becomes a length l2 (>l1) in the external force acting state. In this case, since an external force is not concentrated on the internal indwelling part, operation for further enhancing an external force is performed in some cases, and operation of inserting into a body becomes more difficult. In addition, in the previous catheter kit for a fistula, there is a problem that, when one tries to push and expand an internal indwelling part with an obturator or a hollow rod, at an abutment part, an obturator or a hollow rod breaks a tip of an internal indwelling part, projecting therefrom, and the internal indwelling part can not be inserted in a body. Further, the previous catheter kit for a fistula has a problem that operation of pushing and expanding an internal indwelling part 102 of the catheter 100, and operation of inserting the catheter 100 in stomach must be done at the same time, and an operating ability and operation technique are required as compared with a method of successively performing individual operations.
(Patent Reference 1) U.S. Pat. No. 4,863,438
(Patent Reference 2) Japanese Patent No. 3347315 (claims 1 to 3, FIGS. 5-7)
Accordingly, an object of the present invention is to provide a catheter kit for a fistula having improved operability upon insertion into a fistula of a catheter kit which is used in percutaneous endosopic gastrostomy.